Boat-davit



J.. R. IRWIN.

BOAT DAVIT.

APPLICATION FILED Aus.15. 191s.

1,304,94u Patented May 27, 19,19.

2 sHEETswsHEET x."

Tr -V who l LR. IRWIN.

BOAT DAVIT.

APPLICATION FILED AUG. I5. 191B.

Patented May 27, 1919.

2 SHEETS--SHEET .2.

win

l /7 www! Bly ms Nunn/s Pennes cu namur/o 'Asmncwm u. cv

Asif

UNTED srn'irs To all whom 'it may concern: i l

Be it known that I, JAMES RQ IRw1N,'a citizen of the Unitedv States, residing atthe city and county of San Francisco and State of California, hfave invented'new and useful Improvements in Boat4Davits, 0f which the following is a specification. This invention relates to ship construction, andparticularly pertains to boat davits therefor. Y When a life boat is lowered from a ship, it often happens that the loweringptackle is notfed out from both ends of the boat 'uniformly and that the boat ,is upturned 'with disastrous results.l It is the principalQob-V. ject-of this linvention `to provide a simple means for supporting a life boat upon the deckl of a'ship andpermitting the boat to be raised or lowered without danger of tipping and with minimum manual exertion as coml pared to thatv required in handling boats suspended from d'avits of present day construction.

`The present invention contemplatesv theuse of a pai'rof rigid'uprights to which are pivoted .swinging armsadapted to be simultaneously actuated lby a. mechanism which will vcause theftwoimembers to swing outwardly or inwardly intnison and to carry a tackle from which the opposite endsof `a life boat are dependent, said tackle being provided kwithtwinding means which will uniformly tighten andreleaseboth tackle ropes at once. Y Y Y The invention is illustrated by way of example `in tha-accompanying drawings, in Whiqhfi H vFigure 1 isa view in side elevation, disclosing a lifeboat yas .operatively connected tthedavits. .v j ,A Fig. 2 is agview -in end' elevation, illustrating the" ldavitsand the manner inwhicha life boat is handled, said view further indicating in dotted lines the outer position o Referrin' fto the .y drawings, 10v indicates the ,deck 0f a ship up'ofnwhich are secured uprightbeams 11and12. These beams areV parallel to each other and are bolted to the'y deck by boltsand angle plates 13. As yhere shown, the Vbeams are of/channel'seotion and4 pro-vide runways upon their opposite sides for a-vertically movingwcarriage 14.

The carriage 14 is composed of separate Plates 15:21am? 16 whheextend along opporV siteifaces of the' beam and' are secured to- Specification of Letters Patent.

ATE clarion.

JAMES R. IRWIN, 0F SAN' FRANCISCO, CALIFORNIA.

f BOAT-DAVIT.

Patented May 27, 1919.

Application leaaugust 15, 191s. 'serial No. 249,936.

getherby corner Vpins 17, These pins space the t'wo'plates in relation to each other and alsoV form axles forfrollers 18.` The rollers are arranged Vin pairs along theinnerl and outer facesof the beam and are adapted to roll ther'ealong .The carriages are fitted with Vthreaded lugs 19` through which vertically extending screws 20 are positioned. These screws are journaled to the beam within -bnackets 21 and 22 secu-red at their opposite ends. ,The lower end of each screw is fitted with a gear 23 in meshwithfgears 24. These las-t named gear-s are-fixed u `on a horizontally extending-'operating shaii; 25. This shaft is also journaled in the; standards 11and 12 and may be rotated by cranks 26 and 27 fixed to the opposite ends of the shaft. By this means two `persons may rotate the shaft and exert sucient power to raise the lboat from the water, if desired.

Intermediate the length of the shaft is a worm gear 28, which is in mesh with a worm wheel 29 carried by bearingstandards 30. These standards are fixed .to the floor of the deck and rotatablyvsupport the worm wheel 29 as it is koperated by a crank arm 31. By this mechanism the shaft25 may be operated by a single man, if desired. The standards 30 may also be formed with upwardly extending brackets 32 through which the Shaft 25 extends and by whichl it is stabilized.

Extending through the plates of eachV carriage 14 is a pivot pin V33 which forms a connectionfor links V34. The upper-ends of these links arel pivoted by pins 35KV to swinging booms 36 which are in alinementwith the standards of thefdavits and are secured by bottom, pins 37 within -brackets 38 rfixed vupon the deck. These members are adaptedto Swing through a vertical plane and arel fitted at their free ends,l withvbrackets 3 9V forming aL pivotal support for sheave blocks 40. The sheave blocks may be of any de- Vsired construction land accommodate hoisting cables 41 whichV are led over idlerv pulp leys 41 rotatably secured vto theupperuends of the standards 11 and12.. :The lower run vof each cable'is fitted with a block 42,tok

thus" pre`venti'1wy a premature releasing at either end of the boatwhich .vvouldrpossiblyA overturn it.

.are carried by a standardvO and actuatedby crank arm 51.

drum in'efith'er direction will simultaneously windforunwind the cables. A

The life boat? is supported upony blocks 44 and`45 which aresfecuredfto the deck of the vessel andareespeciallyshaped Vto-convir'fter r` ,the legboat has been swung clear` f lofftheship :the duni`47 maybe rotatedto' pay oiitthehoisting 'cable and:4 thus allow Y the-bat 'to be*i lowered -t'oj the surface ,of the' ivater` afdesire'dl" point vlhas 'beeir reached Ai'n theV travel of thefboat," the hooks form to the hull of thelife boat and to accommodate the keel thereof! withoutpermitting theboatto rock.,A `Each of'theserblockis isV formed in two parte;v the outer. partbeing fastenedto the'deck by ajhinge 46 which` will permit it toy swing vdovvnwardly onto the deckjand to affordfclearance for the'boat, so

f that it inaygswing directlyy outwardly from the' sidejV-o'fj'the ship"l without the necessity olL being raised'. The. two portions of each block are Asecured in their normal upright positions locking rods 46 which extend through openings in 'the' two blocks and hold them against movement. Y Y Y In operation, thelifeuboat is positioned upon .the declro'fthe ship', asshown'in'Fig. 2.' In the'jeve'ntthat `it isltobe lo-weredthe lockingishafts^46jare withdrawn from their.

apertures' to permit'the 'outerportio-ns of the blocks'44`and 45 to swing longitudinally ot the life boat` and to assume positions flat upon thel deck ofthe'ship. vvWhen this has been accomplished ythe shaft 25 may be ro#V tatedibyA the *'crank 31 orthe cranks 26 and" 27 anditlwill'beevident that power may be applied-togallfthree cranks.' This will pro-l duce' a' simultaneous rotation of the )two shafts 2O4 will cause'the carriagesf'1'4 to Amrovefupwardlyalong the standards 1l'. and

As -this'carriaf'ge pursues its upward course. oftravel thetlowerjends o-flvthe links" 3 4 will bef-'raiseda-ndfWillforce'the outer ends ofA tlifesef-linksfoutwardly; This will tend toy Fswingfth'e booms fu'pon their pivots 3,7 fand:

'outwardly to overhang y Y, y

` supported"byrfthef'beamandadaptedfto VcauseI them lto 'sv'vin'g multaneou's'ly"'actuatedifto"i disengageY the freeotthe'hoistingtackles.

f 'It Awillst-e noted :that dueto'thefaet thatA One ofthe cables is ledV onto thedrum from one side and the other cable-V v i over thesides vof `the. ship to tliereaftei'as- 'from the Aopposite side, so that rotating the the Vuprightbeams 11 and 12, there will be may beeasily operated Withoutnexcessive wear-and without the,possibility ofk causing difficulty when the davits are to be used. Y Y i j It will be Vreadily,recognized that inc'ase the boat is to beraised a reverse operationA Willeasily elevate? the. boat Y, and swing.- it in` sume. position( offrest upon, the blocks '44 Y afnd45;` yg d It -will'thusbe seen that the forni o fbooni Y here disclosed embodiessimple andl powerful means "for facili-tatingriin fits. manipulation an'd',`rlfurther,l provides means' whereby two or more davits be simultaneously actuated` by1 mechanism' manually ,-on'eratedv one Yor morepersons. It will alsobe noted that the means for 'actuating the tackle mechanism willinsure speed and certainty inoperation andfca'use vthe boat to behandled, with safety;

*g Having thus described myv invention, what I Claimvandgdesire lto` secure 'byL'etters In device ofthe-characteridescld'; a f iXed' vertical beam, boom. fpivotedl: at

thelower' end of said. beam and swinging Y A in the saine jplane therewith', fa carriage .friction membersf interposed between the? Y carriage" andrthe oppositel sides of 'the `beam,

for facilitatingin themovement of the Acar- 'riagejtherealong,"a'rigid link member piv- Y the carriage 'for'"thedirectisupport'thereof,

a boom adepted-t9 swinsfr0m a pivot at" th'e'jfoot ofithe bea''n;'a'ndin.they same planel th:ere`Witl1,` Y al rigidfli'nkf pivote'd" near -thef andf'a screw member ij extendingv vertically.

raise'and "lower tliebarriagef g Y '3. Boatdavits comprisingvertical stand' ards, verticallyvswinging booms'pivoted 'at t f the lfoot-ol"feachfstandard, carriagesiounted-upon eachfof-said beams for [slidable fverticalf'movementtherealong, Sets of 'rollers Y rotatably supported bythe carriage and 'di'sL-j posed tojbearaga'inst-the oppositefsides jof the standards, rigid linksAi-'pi'votedfto thief;V Carriage by *their* hei'eild's andfpivoted toYV ff the 'outer' ends offthe'lbdoms byitheir other end-s, screw J means-for i simultaneously `frais-'1'`A ing or lowering the carriages, block and tackle mechanism dependent from the outer end of the booms, and means for simultaneously operating said tackle.

4. Boat davits comprising vertical standards, vertically vswinging booms pivoted at vthe foot of each standard, carriages mounted upon each of said standards for slidable vertical movement therealong, sets of rollers rotatably supported bythe carriage and disposed to bear against the opposite sides of the standards, rigid links, each link pivoted to the carriage by one end and pivoted lto the outer endof its boom by the other the standard, a plurali-ty of rollers carried by the side plates and disposed along the opposite edges of the standards, a vertically swinging boom pivoted at the foot of said standard and swinging in the same plane therewith, a rigid link pivoted by its outer end to the free end of the boom and by its inner end to the plates of the carriage, a threaded lug extending outwardly from one plate of the carriage, an elevating screw parallel to the standard and rotatably supy ported by its opposite ends thereon, and

means for operating said screw.

6. In a device of the character described, a pair of davit units each comprising a rigid vertical standard, an. carriage vcarried and mounted thereon, comprising side pla-tes disposed along the opposite sides of the standard, a plurality of rollers carried by the side plates and disposed along the opposite edges of the standards, a vertically swinging boom pivoted at the foot of said standard and swinging in the same plane therewith, a rigid link pivoted by its outer end to the free end of the boom and by its inner end to the plates of the carriage, a threaded lug extending outwardly from one plate of the carriage, an elevating screw parallel to the standard and rotatably supported by its opposite ends thereon, a horizontal shaft journaled by its opposite ends through Ythe two standards, gearing connecting said shaft with the elevating screws and irreversible gearing by which the shaft may be rotated.

7. In a device of the character described, a pair of davit units each comprising a rigid vertical standard, a carriage carried and mounted thereon, comprising side plates disposed along the opposite sides of the standard, a plurality of rollers carried by the side plates'and disposed along the opposite edges of the standards,` a vertically swinging boom pivoted at the foot of said standard and swinging in the same plane therewith, a rigid link pivoted by its outer end to the free end ofthe boom and by its inner end to the plates of the carriage, a threaded lug extending outwardly from one plate of the carriage, an elevating screw parallelto the standard and rotatably supported by its opposite ends thereon, a horizontal shaft journaled by its opposite ends through the two standards, gearing connecting said shaft with the elevating screws and a worm gear carried on the shaft, a complementary worm member in mesh therewith and a crank by which said complementary worm may be operated to roy witnesses.

JAMES R. IRWIN. Witnesses:

JOHN H. HERRING, W. W. HEALEY.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

